Method and apparatus for making nonmetallic sheathed conductors



June 20, 1944. c. w. ABBOTT METHOD AND APPARATUS FOR MAKING NON-METALLIC SI'IEATI'IEDy CONDUCTORS June 20, 1944.- c; w. ABBOTT l2,351,589

IIETHOD AND APPARATUS `FOR MAKING yNOH--METALLIG SHEATHED CONDUCTORS `Filed Aug. 2. 1941 3 Sheets-Sheet 2 METHOD AND APPARATUS FOR MAKING NON-METALLICv SHEATHED CONDUCTORS NNN um@ www .vw r

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Patented June 20, 1944 t `UNITED `STA'IESr PATENT OFFICE 2.351,5!9 U f f Mn'rrron ANn APPARATUS Foa MAKING NoNMn'rAmc Summen coNnUc'roas o charles w. Abbou, Laehmom, N. y. Application August z, 194,1, serial Nn. 405,181

(CL sr-'n Claims.

lThis'invention relates to electrical conductor construction, illustratively` of the type intended o for installation in buildings to form the circuit or circuits usually for lighting, power, and like uses, and` more particularly, to an apparatus and method for making such electrical conductor construction. 'I'his application is a continuation, in part, of my application Serial No. 350,194, filed August 3,1940, since maturedinto Patent No. 2,251,262 of August 5, 1941; o o

One of the objects of this invention is to provide a method and apparatus for making insulated conductor constructions of the abovementioned character in` a simple, eflicient and economical manner., Another object is'to provide amethod and apparatusfor building up an insulating covering or sheathing for a wire or` elec-` trical conductor, including ,one` or more elements that are in tape-likeform and helically wrapped,

y in` which certain complications oi 'both operation and construction that `are vinherent in present methods and apparatus, may be dependably eliminated.` Anotherobject is to provide a method and apparatus in whichan insulating or like coveringmaybebuilt up about a conductor, or the like,` in which adjustment of factors like speed ofi-drive of the winding or wrapping head and in which cost-increasing speed change mechanisms `for achieving such'adjustments, neces-y sary in present-day machines to compensate for various or varying diameters, may be dependably eliminated.` o

Another Objectis to provide a jmethod and apparatus in which the `many operational and structural advantages of fixed lrelative speeds of wire or cable `movement and of rotary movement of the wrapping head or heads, throughout subl stantial changes in diameter oi wrapping',may

be achieved in a thoroughly dependable and prac` tical manner. Another object is in general to simplify and improve heretofore known methods and apparatus for lconstructing a sheath about a core, such'as a wire or conductor, and toprovide a method and apparatus capable of meeting the requirement of winding `or wrapping a coveringelement helically but for diiierent diameters according to the needs of commercial production at" less cost of operation, less ilrst cost of apparatus, at greater emciency'andgreater reliability. Other objects will be in part obvious or in part pointed outhereinafter.

I'he invention accordingly consists in the features of construction, combinations of elements,

o vention',

one Vor more of the others. all as will be illustratively described herein, and the scope of the application of which will be indicated inthe following claims. 1

In the accompanying drawings in which is shown by way of illustration a preferred embodiment of the mechanical features ofmyin- -Figure 1 is a plan view ofl an insulated con-` ductor or cable construction, with parts progressively,` removed or broken away or shown insecv tionf to show the yarious elements and `their structural interrelationships.- illustrating one form'of conductor construction which Vmay be made according to my invention; f

Figures2and 3 are views diagrammatic of the conductor construction ofFigure 1 showing `two identical conductor constructiona'but, respectively, of different radial dimensions to illustrate certain features of how my -methcdand apparatus cope with the different radial dimensions re'- quired in different sizes or relativedimensions of conductor construction; t

Figures 4'L andi'J show respectively the right-` hand half and the left-hand half of aside elevation of a complete illustrative apparatus for carrying out my method, certain vparts being indicated schematically or diagrammatically;

`Figure 5 is a central longitudinal vertical secr tional view on an enlarged-scale of part of the apparatus of Figure 4 showing its relation to the conductor being operated upon; and 1 arrangements oi'v parts, and in the several steps l Figure 6 is adiagrammatic plan view nof an applicator embodied in the apparatus of Figure 4,"

as seen along the lines 6-6 of-Figure `4. i Y

Similar reference characters referto similar parts` throughout the several views of the drawings.

`directly applied to it an initial layer of insulation indicated at l2'. iilustratively 'a layer of rubber or like compound, and of suitable thickness. Thereabout is wound a band or tape-like element I3 Illustratively ofA paper, and if desired, Land as o,

disclosed in my said application, there may be interposed between the jacket l2 and the helical layer formed bythe member I3, a coating Il, as

of lacquer, particularlywhere rthe jacket l2 is of vulcanized rubber, to which is applied a material comprising small particles or flakes, indicated For purposes `of illustration, I have selectedoa o at I4, preferably mica of suitable land preferably very small mesh, and a coating I5 of a suitable wax.

The tape element I 3'may or may not, when helically wrapped. have an overlap of one turn on the next. and for greater simplicity I have shown the element I3 -without an overlap and hence with the adjacent edges of successive turns abutting. In either case, and in the illustrative form of conductor shown, there is then applied over the paper wrap I3 a continuous helix of a cord-like element Il wound at a pitch or lay to y leave a suitable spacing between successive turns somewhat analogous to a form of screw, thread; Member Il may be substantially round in crosssection and is preferably of twisted paper. being thus afform of so-called paper cord and being of relatively tough or strong construction. Next there is applied to the structure, over and into the spaces between successive turns of the helicalcord I1 an` insulating material or compound that is plastic to a suitable degree throughout the operating ranges of temperature of theultimateV conductor construction and preferably vthe material is a relatively quick-setting thermoplastic so that it can be, when heated, more readily applied. Its composition vand its method ofapplication are preferably as describedrin `my aforesaid application to vwhich reference' isV to be made for further details. The layer formed by the cord I'I and the plastic I3 is of suitable thickness. the plastic I3 preferably having binding or adhesive qualitiesy which, coupled with some impregnation of the paper wrap I3 and ofthe helical rib I'I forms a relatively-tough, yieldable and readily flexible sheathing entity overv which is nowhelically `wound atape or bandlike element I9, preferably also ofpaper, and with orfwlthout an Y overlap,` being shown in Figure 1, for greater simplicity, as being without an overlap and hence with the adjacent edges of successive turns abutting. .i f i Next I may apply a` coating of wax-,indicated at 20 and thereafter suitable additional c overing or sheathing may be applied. For example, where a multiple conductor construction is desired as,`for example, two insulated conductors contained within a single external sheath, I may run two constructions likeL that above described, side by side, as in Figure l, where the additional structure is indicated by the reference character f 2l whence an outer covering element 22, such as a braiding of cotton braid, may be applied after iirst applying a suitable sheet material like paper. as indicated at 23 about the twoconductor structures, the paper element l23 functioning as a. barrier or dam to block penetration of such braid-impregnating compound, such as compounds or saturants giving 4the braid covering 22 moisture-proof, fire-resistant and-other characteristics, as it is desired to employ. The braid covering 22 may ultimately be given a finished coating as indicated at 24. Full details of such a construction are disclosed in my aforesaid application.

In making up insulated conductor constructions utilizing one or more wraps of a bandor tape-like material, of which the helical elements I3 and I9 of Figure 1 may, insofar as the broader aspects of my present invention are concerned, be considered as illustrative, the diameter or radius of the helix to be wound necessarily varies as the size of any insulatedvconductor construction or cable ofl given structural characteristics v andmay vary also according to the typeof cable construction to be constructed. According to present day practice winding heads or flyers have to beprovided with speed-change mechanisms usually capable of a wide range of change of speed, to meet such production requirements as changes in radius of the helix or helixes, resulting not only in materially higher first cost and also maintenance of apparatus, but also in the necessity for somewhat precise adjustment and manipulation in operation, oftentimes requiring cut-and-try steps of adjustment with resultant wastage of time, labor and materials.

lSuch disadvantages and shortcomings I avoid according to my invention and to better illustrate certain aspects of the latter reference might ilrst be made to Figures 2 and 3, in Figure 2 of which, let it be assumed, the part or structure about which the first wrap, indicated at I3, corresponding to the element I3 of Figure l. is to be helically laid, is of a diameter of 0.130", and it may-comprisev a conductor IIIn like the conductor I0 of Figure l with a suitable jacket I2a thereover, like the jacket I2 of Figure l. while in Figure 3 the 'corresponding elements Illb and I2b have an external diameter of 0.160" and are to have the helical element I 3b, like the element I3 of Figure l, helically wrapped thereabout.

According to 'my invention and during movement axially of the cores about which the respective elements I3n and I3'J are to beA laid helically, I maintain a xed relation between the rate of axial movement of the core and the number of turns of the vhelical element per unit length of core, for example, sixteen turns of the helical element per linear foot of core, but vary the width of the respective tape elements so that,

as the angle of tape feed varies with increase in.

the diameters upon which they are served. there diagonal dimension of the helical elements'even though their individual widths are different. In Figures 2 and 3, four Vdifferent widths of tape elements are shown, yetthe above-mentioned diagonal dimensions, hereinafter called diagonals, are all of the same magnitude, being indicated by the reference character Z. Where, for example, sixteen turns perk foot of core are to be laid, I vary the just mentioned factors so that 3A." diagonals of the tape'elements, even though the latter are individually of different widths, extend lengthwise or axially of the core. Withv sixteen turns per foot, each turn thus accounts for covering a SA" increment of the core.

For example, with the core of Figure 2 having a diameter of 0.130", the tape-element I3* is of a width of but the angle of lay is such thatva 3A" diagonal ofthe tape element I3.v

ment of the cylindrical surface of the core about which the element I3a is wound. But where thel coreV diameter is 0.160, as in Figure 3, I use for the band or tape element I3b a width of make the angle of'lay larger (illustratively about 31 as at F in Figure 3 as compared with about 25v as at E in Figure 2), and thus achieve the laying of the element I 3h about the core with all of its 3A" diagonals coincident with elements of the cylindrical core surface, thus maintaining sixteen turns of the helical tape element per foot of length of the core. InFigures 2 and 3 it may be assumed that. the adjacent edges of successive turns are abutting though it will be understood that the samev principles are emasuntos i 3 ployed for any degree of overlap of successive turns. e i

Where the conductor structures of Figures 2 and 3 are of the kind described above in connection with Figure 1, I apply the helical rib i1,

also with a fixed number of turns per unit length,

and where it is desired to get a closer spacing between adjacent turns of the rib 'element than, for example.A the V4" spacing that would` result from sixteen turns `per foot of length, I prefer to at iixand HY, spacing them on center durelement, thus reinforcing or closing or sealing suchijunction. r 1 `With the rib elementthus applied andthe plastic i8 applied, ,representing` a layer of the desiredthickness, the diameter of the resultant `core in the structure of Figui-e2 may now be 0.240" and in the structure of Figure 3may now be 0.265". Aboutthe former, the band or tape `element i8, corresponding to `element i8 is now helically applied, but is confined to sixteen turns `per foot of core length and, due to the increased i core diameter, I select a width of 1/2' for the element'iS which, with an angle `of lay of about 42 as at G, `presents%" .diagonale lengthwise `of and geometrically coincident withthe. ele- :ments `of the cylindrical core surface.

, i UDOn the'larger-diametered core of Figure 3 the `band element ISP, corresponding to element i9 of FigureA 1,'is applied, but again in sixteen turnsper foot of core length, and here I give the element i8b a width of 1%" which, with the different angle of lay, about 43 as at H, `fully covers the `onefoot length of underlying core with exactly sixf teen turns, again presenting 1%" diagonals lengthwise of and coincident with the elements of the cylindrical core surface.` `In Figures,A 2

and, these diagonals are indicated at Z, being.

all of the same magnitude.

Thus whatever the radius .of winding of1 the helicaltape element, I maintain the same numf ber ofturns per unit length of the conductor structure, and `achieve full coverageby the helical tape element by changing its width. In Figure 4, I have shown in side elevation a preferred forni. of apparatus to better illustrate certain of the unique advantages of my invention. .'I'hus the apparatus may comprise a frame of any suitableA construction, preferably having two upper spaced frame membersrZi and 28 (Figures 4 and 6) preferably made of channel cross section and held inspaced relation by any suitablev means not shown; suitable uprights, preferably in pairs,

as indicated at 29, 38, 3i, 32 `and 33 form standards Afor the upper frame part 21-28, being also convenientlyof channel shape and having spaced lower `frame members35 and 36, also preferably channel shaped, secured thereto for strength and rigidity of construction.. Y

Supported by the paired `uprights or standards 30, 3i, 32 and 33 and preferably aligned along the longitudinal center line of thel frame are bearings B in which isA rotatably .supported a main `driving shaft 38 driven from any suitable source of motive` power, Illustratively and preferably an electric motor 39 which may be secured to a suitable support inturn secured crosswise of the upperlongitudinal frame members 2l2`8,

the drive from the motor to the shaft 38 being achieved in any suitable way as by the beit `10 f wind` simultaneously more than onerib or cord e element, illustratively two of them, as indicated and pulley drive indicated at 48. v

At the right hand end ofthe frame is supporteda suitable guideflpulley orsheave 42 over 'which the conductor or wire iii is brought to the apparatus from a suitable sourceof supply such as a reel mounted on a let-off stand, not shown.

.Frqm the guide shesve 42 the wire in, in the presentillustrative instance/having `thereon a 4.jacket such as the` jacket iii1L or i2b of Figures `2 @and '3, passes through the hollow shaft `43 which supports and rotates with it a paper pad flyer generally indicatedby the reference character 44, the shaft `43` being) rotatably supported in a suitable bearing structure 45.I which bridges across andtis secured to the'eupper frame inembers'21f-28A and between the 'two bearings of which is accommodated a` drivepulley 46 which is connectedby belt 41 to,a pulley 48 .on the main drive shaft 38, .apulley 48 adjustably` supportedfin any suitable way by the pair of up'- riglits.33 serving as a means to keep the belt 41 at the desired tautness.

Illustratively, the speed of driveof the flyer 44 is 2,000` n.' P. M. and the rate ormcvement ofthe conductor I8 in `a direction toward the left is125' per minute. 9 .l i l The flyer 44 may be of anysuitable construction `and is preferably `of the type, known in the art/that takes `and holds the roll or pad of band or tape-like element substantially coaxially with theaxis of the flyer, and it is such a known type of ilyerthat .is Ashown in Figure 4, feeding the paper element i3 onto and helically about the conductor core, being-provided` with `suitable, tensioningmeans andsuitable means for adjusting itself, `in known manner, lto changes in the-angle of lay. n When rotating at 2,000 R. P. M. and with theconductor core traveling at 125' per minute, the flyer makessixteen revolutions and hence applies sixteen turns of the tape element I3, per foot offconductor core.`

`'iIothe left of the flyer 44 isa tube-like support 5|, `carried by the frame` members21-28 and aligned coaxially with the path of travel of the wire i0 which passes through it; support ii'has sleeved onto it. a suitable number of rolls or pads.

indicated Aat 52 vof tape element i3 of the desired thus to continue the winding operation.

Where the conductor is to have a 'helical rib like the ribelement i1 of Figure 1, it next passes throughfthe hollow shaft 53 of aflyer or headgenerally indicated bythereference character 54,

shaft 53 being mountedv in spaced bearingsin a bearing structure 55 likeithe bearing structure 45 e above described, there being a driving connection from the maindrive shaft, at the above-nien` tioned speedqof 2,000 R. P. M., thus also making sixteenrevolutions per foot oi'l wire core travel,

but preferably` the flyer 54, of known construction,` applies two cord or rib elementssimultane--v ously, in theillustrative embodiment being spaced ward the left through a tubular support 8|, of

suitable length to'carry a suitable number of universally wound packages or cops" 82 of the cord element I1. From the support 8|, cop 82 may be slid oi! toward the right and into the flyer I8. as needed, the packages being double-wound -or otherwise wound in any suitable way to provide the ilye'r 84 with, two strands or cords, as

indicated at 'I1'l and I1! in Figure 4, where it is desired to wind a double helix as above indicated. One of them preferably overlles the helical Junction oi' the underlying 'tape element. v

Where the conductor structure is then toha've applied to it a material like the plastic I8 above described in connection with Figure l,'the conductor structure Vnext passes into and through an applicator tankor chamber 84 conveniently supported in between the two upper frame members I1-28, as appears better-from Figures 4 `and 6. The tank 84 contains the insulating material and also suitable means for insuring its application to the conductor structure. Thus the latter may enter the tank through a suitable guide opening or the like 88 in one end wall of the tank and then pass through a suitable device 88 suitably related to the opposite end wall, the device being in general of the type and form shown in Figure 5. 'and described in greater detail in my abovementioned application. Thus it preferably comprises an internally tapered tube-likegelement having a land portion 88* at `its exitor left-hand end-that'is of uniform inside diameter somewhat lessthan the outside ldiameter oi' the helical rib I1 of the conductor structure so that the latter, as it is drawn therethrough, is vsubjected to some degree of compression, thus to compact the insulating material I8 into and about the conductor structure and also somewhat to compact the helical rib I1. These actions are aided by the tapered internal walls of the part 188 whichguidefthe plastic material and the turns of the helixes I1! and I1' neatly yand snugly intov the restricted throat portionll?.

The moving core is submerged in the plastic compound 14 andy to insureE that it is applied to the ribbed structure, I may provide suitable means such asv two spaced'disk members 88 and 88 mounted within the tank v84 and suitably driven as by a shaft18, the latter having, externally oi' the tank 84, a pulley 1I driven by a belt 12 from a motor 18 carried by the frame as indicated in Figure 4. The internal disk element or elements, as they are thus'driven at a suitable speed, pick up and dispose over and onto the conductor structure suitable quantities of the plastic material which is indicated in Figures 5 and 6 at 1,4. Where the material Vis thermo-plastic, suitable means are provided for maintaining it in the tank 88 at an appropriate temperature and hence consistency and preferably also the member 68 is heated; such heating means are diagrammatically indicated in the drawings at 18 and 18 and may take any suitable form, being conveniently in the form of electrical heating units.

Theconductor structure, now with its diameter substantially increased, passes on, leftward as seen in Figure 4, to have the next'tape or b and element such as the paper tape I9 of Figure l applied thereto and for this purpose a head or flyer like the yer 44 above described may be em- 75 ascuas ley 8| on the flyer shaft 18 connected by belt 82 to pulley 83 on l,the drive shaft 38, and belt tightener pulley 88 adjustably carried in any suitable way by the pair of standards'30 insuring the desired tightness of the belt. Y

'Ihrough such a drive as this, yer 19 is also vdriven at a fixed rate relative to therate of movement of the conductor structure being built up and illustratively the flyer 19, with the conductor or core moving at per minute, may have a speed of 2,000 R. P. M.. thus making sixteen turns perl foot of conductor Vand thus giving the tape element I9 sixteen turns per foot of conductor structure.

But since the core onto which the tape element I9 is wound is of materially greater diameter than that of the core Vabout which the tape element I3 is wound, the width ofthe tape I9, carried in the form of a roll or pad by the flyer 19 is greater as is also the angle of lay, as will be clear from either Figure 2 or Figure 3, as above described.

v'I'hen the conductor passes o n through a tubular member 88 suitably supported by the upper frame elements 21-28 and on this tubular member 88 is sleeved a suitable number of'rolls or pads 81 of thetape element I9, of the desired width, ready to rell the head 19 when the pad in the latter is substantially used up.

Thence the conductor passes about a driven sheave or capstan 88 that is rotatably supported between the frame elements and the pair of standards 29, as by bearing blocks 89 carried by the uprights 29. Capstan 88 is driven from the main drive shaft 38 to give it a peripheral speed equal to the linear speed of travel of the conductor through the apparatus, illustratively 125' per minute, the conductor structure being taken one or'more turns about the capstan to insure uniform rate of movement of the conductor structure, whence the latter passes on, as indicated at 98 to a suitable apparatus, driven in any suitable way, toreel up the conductor structure.

The capstan 88 may have any suitable driving connection with the main drive shaft 38 such as. for example. a worm 92 on the shaft 38 driving a wormvwheel 93 on'a shaft 94 extending transverselyvof the frame and provided with suitable bearing supports in auxiliary frame members generally indicated at 98; shaft 94 carries a spur gear 98 which drives a gear 91 of the capstan 88 through an intermediate gear 98 which may be carried in one end of an arm`99 pivoted to the shaft of the capstan 88 and provided with any suitable means as indicated at |00 whereby the intermediate gear`98 may be swung downwardly away from the spur the drive oi' the capstan.

With the flyers 48 and 19 thus driven to lay sixteen turns per foot of conductor travel at respectively different radii of'winding, thel tape elementsl3'and I9 which they respectively wrap onto the structure are, for the respective radii of winding, of such widths that the sixteen turns completely cover the structure, with a uniform overlap throughout where an overlap is desired, or without an overlap and hence with adjacentv edges i oi' successive turns abutting. With the different widths of these two tape elements, illustratively the widths described above for elements I3* and I8* of Figure 2, the angles oi' lay become such gear 96 and thus interrupt that 3/4" diagonals ofthe tape elements are laid parallel to the axis of the core structure and are `laid substantially coincident with the geometric generating elements of their `respective cylindrical core surfaces.

Were the widths of the twotape elements for heads 4x4 and 19 to be` the same, a different number `of turns per foot of core travel would have to be given the tape element of head 44, because of the smaller radius of winding, than would be given the tape .element of head or flyer 19 which winds at a greater radius, and for each change in ratio of the several radii there would have to be` a corresponding change in the relative speeds of Y the flyers and the rate'` of conductor core travel.`

Also, and as to any one flyer, its speed of drive would have to be changed, for a given width of tape element, were the radius of winding to be changed. According to prior methods and apparatus, complicated and `costly speed change` mechanisms have had to be employed -to meetl the varying requirements imposed by different radii of winding, and cumbersome and oftentimes timeconsuming adjustments of speeds of drive have to be resorted to, and other disadvantages incurred. Thus, for example, an apparatus, ac

cording to prior practice, that would be called `upon to produce successive lots of different sizes or styles of insulated conductor structure would have to be set or adjusted by the operators to operate at a considerable number of different flyer speeds and of relativespeeds between flyers themselves, and speed 'change mechanisms had to be provided to meet such Aa wide variety of different combinations of conditions.

But according to my method and apparatus, I maintain fixed relationships, simplify greatly and make materially less costly the apparatus, and l `also greatly simplify the manual operation and supervision and control of the apparatus. Thus,

for example, with a given ratio of drive of flyery head to rate of conductor core movement, I need only tabulate, for various diameters of conductor core and hence for various radii' of winding of the tape element, the particular width oftape` element with which to load the flyer, providing also a tabulation for any succeeding flyer in the same apparatus. Hence for a givenradius of Winding where only one flyer is employed or for the given radii of winding for the respective tape elements where several flyers are employed, the operator simply loads the one flyer in the one instance or the several flyers in the second instance with the corresponding width or widths of tape element, and lets the apparatus do the rest, whileany subsequent requirement of change of radius Figures 2 and 3, having the same number ofturns per unit length of core, is thus also brought into coincidence with the helical junction, whether it is an abutting junction or an overlapping junction, to hold the adjacent edges of adjacent turns securely in position and in effect to seal and close such junction and any asuman `5 possible gaps or irregularities, where abutting, that may be present. v

Thus, for example, where the size of conductor structure indicated in Figure 2 is to be made.

flyer M is loaded with tape element I3* of width and flyer 19 isloaded with tape element I9l of l/2 "width When that lot of conductors is I run off and should it then be necessary to run ofi' a lot or quantity o'fconductor of the size indicatedin Figure 3, the operator simply changes the loading of flyer 44 by leading it with 11;" tape element I3b and loads flyer -19 with 1"" tape element I9", according to Figure 3. Of course, where the plastic applicator mechanism of Figures 5 and 6 is employed, the throatelement i6 would, of course, be replaced by one of a differently diametered bore to suit such new requirements as thus arise. Preferably, and at suitably spaced points along thepath of the core, I provide suitable means to steady the moving core and to prevent whipping or substantial vibration thereof as it moves along. A convenient location and support for such means, which preferably take the form of suitable bushings through the apertures of which the core passes, comprises the tubular supports for the storage of surplus tape or cord elements. Thus, for example, in the tubular support BI in Figure 4", at the right hand end thereof, I mount abushing IUI, acting the flyer 54. A similar bushing 102 may be l mounted in the right hand end of `the`tubular support 86 in Figure 4b, to steady the now more massive core during action thereon by the flyer 19. 'I'hese bushings preferably have tapered apertures as indicated with respect to the bush- Thus it will be seen that there has 'been provided in this invention a method and construc- `tion in' which the several objects hereinbefore noted Vtogether' with many thoroughly practical advantages are successfully achiev^d. `The method will be seen to be of a thoroughly practical character and well adaptedY to meet. the varying requirements of commercial production vof various types and sizes of insulated conductor and the apparatus will be seen to be greatly simplified, made available at lower first cost. can

be more efllciently maintained and npcratedand dependably eliminates the major disadvantages and shortcomings of heretofore known` appa ratus.

As many possible embodiments may be made of the mechanical featuresof the above inven tion and as the art herein described might be varied in various parts, al1 without departing 65' from the scope of the invention. itis to be understood that all` matter hereinabove set forth, or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a method of applying helical wrapping to a conductive or insulating core, the steps which comprise moving the core axially along a given path at a given speed, helically winding at one point in said path a tape element about said core in a fixed number of turns per unit length oi' core with the tape having a width suilicient to completely cover the core at the radius of winding determined by the diameter of the core in relation to the said xed ynumber of turns, helically winding at a subsequent point in said path a cord element over the taped core and then applying to the corded core a pliant mass of material vand smoothing the latterv during movement oi .the core, thereby increasing the core diameter, and helically winding at a still further point in said path a tape element of greater width than that of said first tape element onto the resultant larger-diametered core in the same number of turns per unit length of core as are given said first taped element, but with the said greater width oi the tape element sufficient to completely cover the core at the greater radius of winding determined by the larger-diametered core in relation to 'the said same ilxed number of turns per unit length of core.

2. In a method of applying helical wrapping to a conductive or insulating core, the steps which comprise moving the` core axially along a given path at a given speed, helically winding at one point in said path a tape element about said core in aflxed number oi' turns per unit length of core with the tape having a width sufficient to completely -cover the core at the radius of winding determined by'the diameter of the core in relation to the said xed number of turns, helically winding at a subsequent point in said path a plurality of cord elements about the moving core with lthe turns of the cord elements spaced axially along the taped core and each element being wrapped in a given number of turns per unit length of core, applying insulating means to the corded core and in the spaces intervening said axially-spaced cord elements, and helically winding at a subsequent point in said patha tape element of greater width than that of .said nrst tape element onto the resultant larger-diametered core in the same number of turns per unit length of core as are given said first taped element, but with the said greater width of the tape element suflcient to completely cover the core at the greater radius of winding vdetermined by the larger-diametered core in relation to the said same fixed number `of turns per unit length of core.

3. An apparatus for insulating a conductor comprising a frame having means for supporting and drawing, at a given linear speed and along a given path, a, wire core, said frame carrying a plurality of means spaced along said path for applying covering element to the core, one of said means comprising a source of supply of tape element and a flyer having means for driving it at a fixed R. P. M. in relation to the speed of movement of said core to helically wind said tape element about the core, whereby the width of the latter to be adequate to completely cover the core at the radius of winding is determlned by the diameter of the core and by the fixed number of turns per unit length o1' core resulting from the fixed relation of flyer R. P. M. to core speed, a source of supply of cord element of substantial thickness and a. flyer for helicallyapplying the cord element to the taped core with means for applying to the corded core a pliant mass of material and for smoothing it thereover during drawing movement of the core, therby materially increasing the core diameter, another of said plurality of means comprising a source of supply of tape element and a flyer drivenin fixed relation to the rate of drive of said first-mentioned' flyer for helically winding said second-mentionedV tape element onto the now larger-diametered core, whereby the width of said second tape element to completely cover the larger core at the latters radius of winding is'determined by whatever is the diameter of said larger core and by the fixed number of turns per unit length of core resulting from the fixed relation between the drive of said second fiyer and the drive of said first flyer.

4. An apparatus for insulating a conductor comprising a frame having means for supporting and drawing, at a given linear speed and along a given path, a wire core, said frame carrying a plurality of means spaced along said path for applying covering elements to the core, one of said means comprising a source of supply of tape element and a yer having `means for driving it at a fixed R.`P. M. in relation tothe speed of movement of said core to helically wind said tape element about the core, whereby the width oi v`the latter to be adequate to completely cover the core at theradius of winding is determined by the diameter of the core and by the xedrnumber of turns per unit length of core resulting from the xed relation of flyer R. P. M. to core speed, means forming a. source of supply forv a plurality-of cord elements of substantial' thickness and flyer means for helically applying said cord elements to the taped core with the turns of the cord elements spaced axially along the taped core with means for applying to the corded core apliant mass of material and for smoothing it thereover during drawing movement of the core, thereby materially increasing the core diameter, and another of said plurality of means comprising .a source of supply of tape element and a flyer driven in fixed relation to the rate of' drive of said firstmentioned iiyer for helically winding said second-mentioned tape element onto the now larger-diametered core, whereby the width of said second tape element to completely cover the larger core at the latters radius of winding is determined by whatever. is the diameter of said larger core and by the fixed number of turns per unit length of core resulting from the fixed relation between the drive of said second flyer and the drive of said first flyer.

CHARLES W. ABBOTT. 

